National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Fair

67°F

19°C

Humidity 84%
Wind Speed Calm
Barometer 30.15 in (1021.0 mb)
Dewpoint 62°F (17°C)
Visibility 10.00 mi
Last update 16 Aug 12:56 am EDT
Extended Forecast for

Belle Terre NY

  • Overnight

    Overnight: Mostly clear, with a low around 69. Light northeast wind.

    Low: 69 °F

    Mostly Clear

  • Sunday

    Sunday: Increasing clouds, with a high near 79. Northeast wind 5 to 11 mph becoming south in the afternoon.

    High: 79 °F

    Increasing
    Clouds

  • Sunday Night

    Sunday Night: Showers, mainly after 11pm. Low around 70. South wind 13 to 17 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 70 °F

    Showers

  • Monday

    Monday: Showers, mainly before 2pm. High near 80. South wind 8 to 13 mph becoming west in the afternoon. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 80 °F

    Showers

  • Monday Night

    Monday Night: Partly cloudy, with a low around 71. North wind 5 to 7 mph.

    Low: 71 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Sunny, with a high near 81.

    High: 81 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 69.

    Low: 69 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 84.

    High: 84 °F

    Sunny

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers after 2am. Partly cloudy, with a low around 71.

    Low: 71 °F

    Mostly Clear
    then Chance
    Showers

Detailed Forecast

Overnight
Mostly clear, with a low around 69. Light northeast wind.
Sunday
Increasing clouds, with a high near 79. Northeast wind 5 to 11 mph becoming south in the afternoon.
Sunday Night
Showers, mainly after 11pm. Low around 70. South wind 13 to 17 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Monday
Showers, mainly before 2pm. High near 80. South wind 8 to 13 mph becoming west in the afternoon. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Monday Night
Partly cloudy, with a low around 71. North wind 5 to 7 mph.
Tuesday
Sunny, with a high near 81.
Tuesday Night
Mostly clear, with a low around 69.
Wednesday
Sunny, with a high near 84.
Wednesday Night
A 30 percent chance of showers after 2am. Partly cloudy, with a low around 71.
Thursday
A 40 percent chance of showers. Partly sunny, with a high near 81.
Thursday Night
Partly cloudy, with a low around 67.
Friday
Mostly sunny, with a high near 78.
Friday Night
Partly cloudy, with a low around 66.
Saturday
Mostly sunny, with a high near 77.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Belle Terre NY
 40.96°N 73.08°W (Elev. 3 ft)
Last Update:
2:28 pm EDT Aug 15, 2026
Forecast Valid:
1am EDT Aug 16, 2026-6pm EDT Aug 22, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation